I am really struggling with my machine, since several months it crashes/shuts down repeatedly. It is always the same behaviour, the power just goes out, no program crashes, no spinning beach balls, no nothing, just a blank screen and of course no power. It can happen while browsing or while watching Youtube or just while creating a simple document. It really is random.I have done everything I possibly could including: 1. Full re-install after clearing the HDD and overwriting it several times with "0"2. Booting and running from an external drive with same OS3. Running both the small and big hardware tests without any indication of errors4. Running memory-tests and also replacing the old 2x2 GB with 2x4 GB of RAM4. Have had it plugged in directly to the wall outlet and together with other machines in a plug board5. Left the machine a service shop and they did the same things but could not get the machine to crash in two weeks(ARGH!)6. Went back to the service shop and they had the machine running for a month straight without any crash/shutdown. None of the above has made any difference at all. I collected my machine from the shop again recently and the first random shut down appeared afte les then 24 hours, it has crashed 3 times since then.The system log does not show anything that can give it away. It seems like I can induce the crash by multitasking and having a lot of tabs open running flash in the browser, but I get no errors in the logs to indicate that I am right, but the crashes mostly happen when I browse (but that is also what the machine is used for 90% of the time) I use Chrome, Safari and Firefox randomly. I have found numerous posts on different forums from people stating the exact same thing, I really like Apple but this is unbearable to say the least, there is officially nothing wrong with my machine since it happens randomly, without any error messages, but I can not use my computer since it can shut down at any given time. What to do? Thanks in advanceAndreas

Answers in Swedish is ok